• 대한산업공학회지
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• 제28권4호
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• pp.435-442
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• 2002

It is difficult to access and share design data among heterogeneous CAD systems. Usually, different CAD systems exchange the design data using a neutral format such as IGES or STEP. A prototype CAD system which uses a geometric kernel and a commercial database management system has been implemented. The prototype system used the Open Cascade geometric kernel and the commercial object-oriented database ObjectStore. STEP provides the database schema. The database can be accessed from commercial CAD systems such as SolidWorks or Unigraphics. The data access module from a commercial CAD system is developed with the CAD system's native API, ObjectStore API functions, and ActiveX.

• 한국CDE학회논문집
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• 제7권4호
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• pp.240-247
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• 2002

Most commercial CAD systems provide parametric modeling functions, and by using these capabilities designers can edit a CAD model in order to create design variants. It is necessary to transfer parametric information during a CAD model exchange to modify the model inside the receiving system. However, it is not possible to exchange parametric information of CAD models based on the cur-rent version of STEP. The designer intents which are contained in the parametric information can be lost during the STEP transfer of CAD models. This paper introduces a hybrid CAB model translator, which also uses the feature tree of commercial CAD systems in addition to the macro file to allow transfer of parametric information. The macro-parametric approach is to exchange CAD models by using the macro file, which contains the history of user commands. To exchange CAD models using the macro-parametric approach, the modeling commands of several commercial CAD systems are analyzed. Those commands are classified and a set of standard modeling commands has been defined. As a neutral fie format, a set of standard modeling commands has been defined. Mapping relations between the standard modeling commands set and the native modeling commands set of commercial CAD systems are defined. The scope of the current version is limited to parts modeling and assemblies are excluded.

• 산업공학
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• 제7권1호
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• pp.67-74
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• 1994

In this study, we propose an integrated CAD(Computer Aided Design) library database in a heterogeneous commercial ECAD(Electronic CAD) environment. To effectively solve engineering problems focused on BOM data extraction we use a software system called schematic capture and company-wide standard electronic part information loaded on different commercial ECADs. We unify many commercial ECADs into one schematic capture and a variety of PCB(Printed Circuit Board) design tools. For this purpose we develope a model for linking CAD symbol library with company-wide standard part information. We also develope a schematic design data conversion scheme and show how to extract PBA level BOM data using our customized schematic capture. This system is being operated in an X-Window based engineering work station and commercial RDBMS base.

• 한국CDE학회논문집
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• 제6권4호
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• pp.254-262
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• 2001

It is not possible to exchange parametric information of CAD (Computer Aided Design) models based on the current version of STEP (Standard leer the Exchange of Product model data). The design intent can be lost during the STEP transfer of CAD models. The ISO Parametrics Group has proposed the SMCH (Solid Model Construction History) schema in June 2000 that includes structures fur exchange of parametric information. This paper proposes the macro parametric approach that is intended to provide capabilities to transfer parametric information. In this approach, CAD models are exchanged in the form of macro files. The macro file contains user commands which are used in the modeling phase. To exchange CAD models using the macro parametric approach, modeling commands of commercial CAD systems are analyzed. Those commands are classified by the grouping method suggested by Bill Anderson. As a neutral file format, a standard modeling commands set has been defined. Mapping relations between the standard modeling commands set and the native modeling commands set of commercial CAD systems are defined.

• International Journal of CAD/CAM
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• 제2권1호
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• pp.13-21
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• 2002

It is not possible to exchange parametric information of CAD models based on the current version of STEP. The design intent can be lost during the STEP transfer of CAD models. The Parametrics Group of ISO/TC184/SC4 has proposed the SMCH schema, which includes constructs for exchange of parametric information. This paper proposes a macro-parametric approach that is intended to provide capabilities to transfer parametric information including design intents. In this approach, CAD models are exchanged in the form of macro files. The macro file contains the history of user commands, which are used in the modeling phase. To exchange CAD models using the macro-parametric approach, the modeling commands of several commercial CAD systems are analyzed. Those commands are classified and a set of standard modeling commands has been defined. Mapping relations between the standard modeling commands and the native modeling commands of commercial CAD systems are defined. The scope of the current version is limited to parts modeling, not assemblies.

• 한국CDE학회논문집
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• 제13권4호
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• pp.255-264
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• 2008

Research that reconstructs a 3D model from a freehand 2D sketch has gained attention since 1990s, when data integration in the CAD/CAPP/CAM/CNC chain was an important issue. However, 2D sketches in the conceptual design phase have not been integrated with the downstream CAD/CAPP/CAM/CNC chain. In this paper, we present a method to interface a freehand sketch modeling to commercial CAD systems by mapping a sketch modeling history to the macro parametric history. We use an extended ISO10303-112 standard to represent the modeling history in a gestural modeling system and translate sketch files to neutral macro files. Macro parametric translators are used to translate netural macro files to commercial CAD files.

• 한국산업융합학회 논문집
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• 제7권4호
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• pp.377-382
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• 2004

This research was about implementing STEP for data exchange among different commercial package(CAD system). STEP was used to share CAD data as follows. ST-Developer implement Solid model was used with a physical file of STEP and represented in a CAD system. And then STEP conversion utility was used to make a neutrality format form in a component modeling. Analysis of Solid model was made possible for CAD system to read in and analyzed Solid model. This research are summarized as follows 1. A basis Model development used Visual C++ for a neutrality data of a programming interface general-use CAD system, and produced Box and Cylinder to a physical file, the result was implemented this in a programming interface to general-use CAD system, it is represented in CAD system as identical one modeling object. 2. STEP was used in different CAD system to utilize to its of each CAD system maximum, CATIA V5R9 user was able to analyze MDT 6 Modeling Arm. 3. STEP was used able to interpret and remodel the existing Solid model.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1340-1345
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• 2003

In this paper, an integrated optimal design software system for structural components has been developed which interfaces existing commercial codes for CAD, CAE and Optimization. They include specialized optimal design software codes such as iSIGHT and VisualDOC, optimization module imbedded in CAD software developed by CAD developers, and optimal design software systems based on API of commercial CAD software. The advantages of the CAD imbedded optimal design approach and those of specialized optimal design software are taken to develop the system. The user defines optimal design formulation in the user interface for problem definition in the CAD control stage, where design variables are directly selectable from the CAD model and various properties and performance functions defined. The commercial CAD codes, Open I-DEAS are used for the development. The resulting software is minimally connected to CAD and CAE systems while keeping maximum independence from each other. This assures flexibility and freedom for problem definition. Fatigue life optimization is taken as a nontrivial application area. As a specific example, the shape design of a knuckle part of an automobile is performed, where the minimum fatigue life over the material domain in terms of the number of cycles of a curb strike are maximized under the constraint of not exceeding the current mass. The fatigue life has been improved by four times of the initial life. The developed software is illustrated to maintain the advantages of existing optimal design software systems while improving independency and flexibility.

• 한국CDE학회논문집
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• 제11권6호
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• pp.422-428
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• 2006

In this paper, an NC data optimization approach for enhancing 5-axis machining speed is presented. It is usual to use expensive commercial CAD/CAM programs for NC data of 5-axis machining, since it needs very large calculations for optimal tool positioning and orientation, tool path planning, and collision-free tool path generation. Since commercial CAD/CAM systems have similar functions and efficiency based on common algorithms of reliable theories, they do not have their own unique features for machining speed and efficiency. In other words, most commercial CAD/CAM systems consider only the characteristics of part geometry to be machined, which means that they generate almost the same NC data if the part to be machined is the same, even though different machines are used for the pin. A new approach is proposed for optimizing NC data of 5-axis machining, which is based on the characteristics of the machine to be operated. As a result, the speed of 5-axis machining can increase without losing machining accuracy and surface quality.

• 한국정밀공학회지
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• 제15권11호
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• pp.21-31
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• 1998

This study described computer aided die design system for cold forging of non-axisymmetric parts. To design the die of cold forging. an integrated approach based on a rule-base system and commercial F. E. code were adopted. This system is implemented on the personal computer and its environment is a commercial CAD package named as AutoCAD. The system includes four modules. In the initial data input module, the variables which are necessary to design of die are inputted by user and die material are selected from the database. In the analysis and redesign module, stress distrubution action on the designed die is analyzed by commercial FEM code NISA II. The designed die is modified to prevent failure in both states of stress free and pressurizing. The developed system provides powerful capabilities for die design of non-axisymmetric parts.